Water, Sanitation and the Modern City: Colonial and Post-colonial Experiences in Lagos and Mumbai

human development, water, sanitation

QuickMMCTest - Quick Multiple Monte Carlo Testing

Multiple hypothesis testing is widely used to evaluate scientific studies involving statistical tests. However, for many of these tests, p-values are not available and are thus often approximated using Monte Carlo tests such as permutation tests or bootstrap tests. This article presents a simple algorithm based on Thompson Sampling to test multiple hypotheses. It works with arbitrary multiple testing procedures, in particular with step-up and step-down procedures. Its main feature is to sequentially allocate Monte Carlo effort, generating more Monte Carlo samples for tests whose decisions are so far less certain. A simulation study demonstrates that for a low computational effort, the new approach yields a higher power and a higher degree of reproducibility of its results than previously suggested methods

Healthcare Utilization Analysis for Housing First Program in Anchorage Alaska

Presented to the Faculty of the University of Alaska Anchorage In Partial Fulfillment of Requirements For the Degree of MASTER OF PUBLIC HEALTHHomelessness, especially for the chronically homeless individual with substance abuse issues, often results in high use of emergency services, depression, loss of hope, increased victimization, poor medical care of chronic conditions, and intense suffering for the individual affected. Proponents of the Housing First model believe that housing is a human right, a need, and should be made available to all for basic human dignity. The primary purpose of this study was to answer the question of whether a Housing First model example in Alaska has impacted healthcare utilization for this specific population. Data on hospital visit numbers and hospital costs were collected from both a tenant and a control sample, for the 2011-2013 period, from three area hospitals. Initial findings indicated there was higher outpatient healthcare service use for the tenant sample after obtaining supportive housing. The control sample also showed statistical significance for an increase in emergency services costs, which was not evident for the tenant sample. Future Housing First programs in Alaska may provide improved healthcare for individual tenants by increasing utilization of outpatient services.Signature Page / Title Page / Abstract / Table of Contents / List of Figures / List of Tables / Introduction / Background / Project Goals and Objectives / Methods / Results / Discussion / Strengths and Limitations / Public Health Implications / Conclusions and Recommendations / Reference

A Framework for Monte Carlo based Multiple Testing

We are concerned with a situation in which we would like to test multiple hypotheses with tests whose p-values cannot be computed explicitly but can be approximated using Monte Carlo simulation. This scenario occurs widely in practice. We are interested in obtaining the same rejections and non-rejections as the ones obtained if the p-values for all hypotheses had been available. The present article introduces a framework for this scenario by providing a generic algorithm for a general multiple testing procedure. We establish conditions which guarantee that the rejections and non-rejections obtained through Monte Carlo simulations are identical to the ones obtained with the p-values. Our framework is applicable to a general class of step-up and step-down procedures which includes many established multiple testing corrections such as the ones of Bonferroni, Holm, Sidak, Hochberg or Benjamini-Hochberg. Moreover, we show how to use our framework to improve algorithms available in the literature in such a way as to yield theoretical guarantees on their results. These modifications can easily be implemented in practice and lead to a particular way of reporting multiple testing results as three sets together with an error bound on their correctness, demonstrated exemplarily using a real biological dataset

Negative Luminescence

The increasingly pervasive phenomenon of light pollution spans several different fields of concern, including the loss of the night sky, energy wastage, and the effects of artificial light on circadian rhythms and nocturnal ecology. Although the scale of the problem has grown significantly in recent decades, the underlying dynamics remain only partially understood beyond the identification of specific technological pathways such as the rise of light-emitting diodes (LEDs) or the capitalist transformation of the nocturnal realm. It is suggested that current approaches to the study of light, including the identification of “urban atmospheres,” the elaboration of existing approaches to urban ecology, or the extension of “smart city” type discourses, do not capture the full complexity of the politics of light under late modernity.European Research Counci

The chopthin algorithm for resampling

Resampling is a standard step in particle filters and more generally sequential Monte Carlo methods. We present an algorithm, called chopthin, for resampling weighted particles. In contrast to standard resampling methods the algorithm does not produce a set of equally weighted particles; instead it merely enforces an upper bound on the ratio between the weights. Simulation studies show that the chopthin algorithm consistently outperforms standard resampling methods. The algorithms chops up particles with large weight and thins out particles with low weight, hence its name. It implicitly guarantees a lower bound on the effective sample size. The algorithm can be implemented efficiently, making it practically useful. We show that the expected computational effort is linear in the number of particles. Implementations for C++, R (on CRAN), Python and Matlab are available.Comment: 14 pages, 4 figure

Implications of moderate altitude training for sea level endurance in elite distance runners

Elite distance runners participated in one of two studies designed to investigate the e ects of mod- erate altitude training (inspiratory partial pressure of oxygen »115±125 mmHg) on submaximal, maximal and supramaximal exercise performance following return to sea-level. Study 1 (New Mexico, USA) involved 14 subjects who were assigned to a 4-week altitude training camp (1500±2000 m) whilst 9 performance-matched subjects continued with an identical training programme at sea-level (CON). Ten EXP subjects who trained at 1640 m and 19 CON subjects also participated in study 2 (Krugersdorp, South Africa). Selected metabolic and cardiorespiratory parameters were determined with the subjects at rest and during exercise 21 days prior to (PRE) and 10 and 20 days following their return to sea- level (POST). Whole blood lactate decreased by 23% (P < 0.05 vs PRE) during submaximal exercise in the EXP group only after 20 days at sea-level (study 1). However, the lactate threshold and other measures of running economy remained unchanged. Similarly, su- pramaximal performance during a standardised track session did not change. Study 2 demonstrated that hypoxia per se did not alter performance. In contrast, in the EXP group supramaximal running velocity de- creased by 2% (P < 0.05) after 20 days at sea-level. Both studies were characterised by a 50% increase in the frequency of upper respiratory and gastrointestinal tract infections during the altitude sojourns, and two male subjects were diagnosed with infectious mononucleosis following their return to sea-level (study 1). Group mean plasma glutamine concentrations at rest decreased by 19% or 143 (74) lM (P < 0.001) after 3 weeks at alti- tude, which may have been implicated in the increased incidence of infectious illness